The QCD vacuum probed by overlap fermions

TL;DR

This paper investigates the QCD vacuum using overlap fermions, analyzing eigenmodes to understand topological structures, localization, and duality at different scales, combining instanton and defect pictures.

Contribution

It applies overlap fermion eigenmodes to analyze the QCD vacuum, unifying instanton and defect models across scales with new eigenmode-based techniques.

Findings

Localization and chiral properties of lowest modes characterized

Overlap-based topological charge density compared with field strength tensor

Identification of domains of (anti-)selfduality and dual vacuum picture

Abstract

We summarize different uses of the eigenmodes of the Neuberger overlap operator for the analysis of the QCD vacuum, here applied to quenched configurations simulated by means of the Luescher-Weisz action. We describe the localization and chiral properties of the lowest modes. The overlap-based topological charge density (with and without UV-filtering) is compared with the results of UV-filtering for the field strength tensor. The latter allows to identify domains of good (anti-)selfduality. All these techniques together lead to a dual picture of the vacuum, unifying the infrared instanton picture with the presence of singular defects co-existent at different scales.